Field of the Invention
The invention relates to a cooling circuit with a combustion engine, a coolant cooler, a first thermostat, a first pump, a condenser, a second thermostat and a second pump, wherein a coolant can flow through the cooling circuit, wherein the combustion engine, first pump, coolant cooler and first thermostat are arranged in a first circuit.
Description of the Background Art
To reduce fuel consumption in motor vehicles, systems can be used which utilize the energy bound in the hot exhaust gas. For this purpose, for example, waste heat recovery systems (WHR systems) can be used. The thermal energy of the exhaust gas is thereby converted into mechanical energy, which can be introduced, for example, in the drive train to thus support the propulsion of the vehicle. Alternatively, the mechanical energy can be used for generating electrical energy to, for example, operate a generator. The electrical energy generated can, for example, be supplied to the onboard electrical system, or temporarily stored in an energy storage device. For the conversion of the thermal energy, a thermodynamic cyclic process can be used. A working fluid can thereby be vaporized by the thermal energy of the exhaust gas and then relaxed in an expander with the release of mechanical energy. The resulting process heat can be advantageously dissipated via a cooling circuit. Preferably, the heat is removed at the lowest possible coolant temperature, while at the same time ensuring that it does not fall below a certain minimum temperature, which will depend on the physical properties of the working fluid.
For cooling, the cooling circuit may be used which is also used to cool the combustion engine. Alternatively, a separate, additional cooling circuit can be provided.
One disadvantage of the solutions in the prior art is in particular that additional outlay is caused by the additional cooling circuit for cooling the WHR system, which makes the system more complex and more costly. When using the cooling circuit of the combustion engine for the WHR system, problems arise with regard to the temperature in the cooling circuit because the temperature level of the coolant in the combustion engine is higher than the temperature level of the coolant in the WHR system. This results in adverse mutual influencing of the coolant temperature.
This problem also exists in other applications with one or more heat sources that additionally need to be cooled, and is not limited to vehicles with a WHR system. One example for other applications of the invention is the cooling of the electronic components in a hybrid vehicle. For the sake of simplicity, the below example refers to a WHR system.